1. Field of the Invention
The present invention relates to a pressure relief valve for a container and more particularly to a pressure relief valve for a container having a liner therein whereby when pressure builds up in the liner, the pressure relief valve automatically operates to puncture the liner and relieve the pressure therein.
2. Description of the Related Art
Containers of various types and sizes are known in the art which have a wide variety of uses, such as for storing and transporting food products. Collapsible or knock down containers are known which are made entirely or substantially entirely from plastic materials using a molding technique known as injection molding. Such containers have a pallet type base with sidewalls and endwalls pivoted to the base and adapted to move from a folded position on the pallet to an erect position for holding goods. Many of such containers have a lid for closing the top thereof. Such containers are commonly used in the storage and transportation of fluids, such as tomato paste or other food products which are perishable. The products are often contained in a liner or bag within the container. On occasion, products such as tomato paste become contaminated with bacteria resulting in a dangerous pressure buildup within the liner. When the pressure buildup becomes extreme, the liner expands and explodes and splits containers open and the contents spewed out. When this happens, it is possible to cause injury to workers, particularly when a plurality of such containers are stacked and a number of the containers on the stack explode, causing a stack failure.
Thus, a need exists for a means for relieving pressure buildup in a container having a liner therein filled with food products such as tomato paste so that the containers are not split open.